Core bit



Dec. 5, 1939. c. J. KOEBEL I 2,182,562 00125311."

Original Filed Jan. 23, 1937 165 J'A Mkz Patented Dec. 5, 1939 UNITED STATES" 2.182.582 GORE BIT Charles J. Koebel, Detroit, Mich.

Application January 23, 1937,

Renewed November 3, 193

2 Claims. (01. ass-'72) her having cutting elements on its end, and rotation oi the bit about its longitudinal axis results in the cutting of an annular opening and thereby separates a central core from the strata through which the bit is operated. In order that and others may accurately determine of various strata it is important that the core remain unbroken as much as possible so that the position of diiIerent elements in the core may accurately be determined longitudinally thereof. It is therefore important that the bit should cut efflciently so as to obtain a smooth and nonroken core and also that it last or be durable.

Oneobject of the present invention is to provide an improved core bit which will last for a longer period of time and w ch will enable obtaining a smooth and non-broken core.

Another object of the invention is to provide an improved core bit-wherein the diamonds may be distributed uniformlyand with the diamonds projecting equal amounts so as to thereby enable obtaining a uniform distribution of the cutting forces. and to prevent uncut portions of the strata from engaging the metal that holds the diamonds.

Another object of the invention is to provide an improved core bit that may be altered, repaired or renewed readily by diamond setters in the field.

Other objects of the invention will become apparent from the following specification, the drawing to which it relates, and from the claims hereinafter set forth.

For a better understanding of the invention reference may be had to the drawing wherein Fig. 1 is an end view of a core bit constructed according to one form of the invention.

Fig. 2 is a cross sectional view taken substantially along the line 2-2 01 Fig. '1.

Fig. 3 is a detailed view illustrating one of the lugs forming a part of the bit shown by Fig. 1.

Fig. 4 is a view generally similar to Fig. 1 but illustrating another form of the invention.

Figs. 5, 6 and 7 are views similar to Fig. 2 but illustrating still other forms of the invention.

Referring to Figs. 1 and 2, the body of the core bit is indicated at Ill, and it will be understood thatthisistobeiastenedtotheendotarotary drill shaft of tubular spaced slots ll, slots have a substantial depth linearly of the body. In each of the slots a slug l2 of comminuted metal alloy is disposed and the slug is securely fastened in place in any suitable manner, such as bybrazing or by peening 10 of the body metal over portions of the slug metal. The slugs might also becast in place in which event they would become tightly bound in the slots. Brazing is indicated at l3 in Fig. 2 and this brazing may be eflfected also along the sides of the slug. Each of the slugs is provided with Figs. 1 and 2, the staggered so that one diamond won't follow in the cutting path of an adjacent diamond. The end desired in this connection is that the cut-. 5 ting loads will be equally distributed over all of the diamonds to avoid premature wearing of any one or more diamonds and. also to insure complete removal of the rock as the bit progresses to avoid uncut portions of the rock engaging the slug or body metal between the diamonds. If such engagement of uncut portions of the rock with the body or slug metal were permitted the body and slug metal would wear away and the anchorage of the diamonds might thus become impaired. v

Slugs of comminuted alloy with diamonds imbedded therein may be made according to the processes disclosed in the patent to Koebel No. 1.848.182, or in the application for patent referred to therein, Serial No. 586,238, filed Janumy 12, 1932. In the present case, however, it may be mentioned that the diamonds would only be distributed along the cutting peripheral por- V tions of the slug although if found desirable the diamonds might be distributed throughout the comminuted alloy slugs and then as the diamonds wore down, the slug and body metalwould necessarily wear away so as to expose new dia-, mond points. 5 Fig. 4 is similar to Fig. 1 and in this structure slots l6 are provided that are angled to radii. In this construction a somewhat greater circumferential space will exist between the radially outer portions of the slugs for accommodating 5 additional diamonds or smaller slugs to be referred to hereinafter, and which ordinarily would be inserted by diamond setters in the field. Moreover the strength of the slugs is slightly greater because of their angled positions, and it is a little easier to distribute and to stagger them.

In the construction shown by Fig. 5 peripherally extending slugs l8 of substantially greater length are provided and each of these may have a rib portioniil adapted to fit in a groove 20 in the end face of the body. The slugsmay be held in position by peening over the metal as indicated at 2| or by other suitable means such as brazing as hereinbefore mentioned. The adjacent'ends of the slugs brazing such as indicated at 22, and if desired a portion of the body Id may extend between the ends of the slugs and the ends of the slugs be brazed to the body portion.

The structure shown by Fig. 6 is substantially the same as that shown by Fig. 2 excepting that small comminuted alloy slugs 24 are provided in the side wall of the body ill. The slugs shown are ground and have small diamonds projecting beyond the side surface of the body. Such slugs would be distributed circumferentiaily and would be staggered so that one diamond would not exactly follow the cutting line of an adjacent diamond. It will be understood that the slugs are held in place by brazing, peening, or other suitable means and if desired the opening for the slug may be tapered and the: slug tapered corre spondingly.

In the structure shown by Fig. 7 instead of using the type of slug shown by Figs. 1, i, and 5, slugs such as indicated at M in Fig. 6 are used. These slugs are distributed over the side surfaces of the body I0, as well as the end face. It will be appreciated that the use of small slugs having diamonds imbedded therein in a structure such as this or such as shown in Fig. 6 readily enables the diamond setters in the field to properly insert diamonds without any difilculty; It would only be necessary to drill the same type of holes at all points and insert the slugs, and

may be connected by then secure the latter in place by peening or bra!- ing. No conventional setting of diamonds would be necessary.

It will be understood that small slugs such as shown at 24 in Figs. 6 and '7 could be employed at various points in any of the other structures shown. For example, such slugs could be used in the side wall of the body such as illustrated in Fig. 6 or sockets could be drilled between the slugs I2 and IS in Figs. 1 and 4 for receiving the slugs 24: Also, could be formed partly in the slugs l2 or 15 and partly in the metal between the latter slugs. In other words, slugs 24 could be inserted at any desired point over the working surfaces of the bit.

Although more than one form of the invention has been described and illustrated in detail, it will be apparent to those skilled in the art that various modifications may be made without departing from the scope of the appended claims.

What is claimed is:

1. A core bit comprising a tubular body, the

tubular wall of .said body being rounded in radial cross section at one end and provided with transverse slots therethrough, segmental slugs seated in said slots and conforming in contour to the inner and outer walls of said tubular body as well as to the radially rounded cross section of said tubular wall, said slugs forming with the intervening end portions of said tubular body a nose for the core bit, said slugs comprising sintered comminuted metal alloy each having embedded therein a plurality of cutting stones.

2. In a core bit, a tubular body having one and rounded in radial cross-section and provided with transverse slots of substantially equal width throughout their length; and reversible slugs, of substantially equal width throughout their length and having a rounded surface at one end conforming substantially tothe rounded end of the tubular body, seated in said slots; and a plurality of diamonds arranged in a curved series on the rounded surface of each slug.

CHARLES J.

such sockets for additional slugs 24 

